Tag: geoengineering

The yellow and brown on this map of the western Canadian coast represent high concentrations of chlorophyll.

A California businessman lobbed 110 tons of iron into the ocean off the western coast of Canada this July, The Guardian revealed on Monday, and he did it in violation of two international moratoria on such activity. Russ George wanted to stimulate the growth of phytoplankton to sell carbon credits for the carbon dioxide that the tiny photosynthesizing organisms would take out of the atmosphere. Satellite images from August (above) showed that about 10,000 square kilometers of ocean greenery had already grown.

Venice is sinking, and the nearby Adriatic sea—like the global sea level—is rising. The city could, some estimates suggest, be underwater by the end of the century. Much of the trouble is due to Venice’s precarious, low-lying position in the middle of a lagoon, but human activity in the area has played a role in the city’s subsidence, as well. As Scott K. Johnson explains at Ars Technica:

The pumping of shallow groundwater in the mid-1900s also contributed to the problem. Water in the pores between grains of sediment provides pressure that bears some of the load. When pore pressure decreases, or water is removed completely, grains can be packed together more tightly by collapsing the pore spaces. As sediment is compacted, the land surface drops. While the effect was small (less than 15cm), Venice doesn’t have much wiggle room.

A recent volcanic eruption let scientists watch Mother Nature try out one of the geoengineering schemes that has been proposed to reduce the amount of carbon dioxide in the air, and therefore cool the planet. But the results of this natural experiment left a lot to be desired.

The geoengineering technique known as ocean fertilization calls for scientists to dump iron into the ocean to “fertilize” it and spur blooms of phytoplankton. These tiny photosynthetic organisms will suck up CO2 as they grow, the thinking goes, but will then die and tumble down to the sea floor, where the CO2 will be safely stored in the heaps organic matter.

The same thing can happen naturally, though, if a volcano happens to erupt and spews iron particles over the ocean. That’s exactly what happened in the summer of 2008.

In August 2008, scientists in the northeastern Pacific Ocean were shocked to witness a sudden, huge spike in the area’s plankton population. Their investigation traced the bloom to an ash cloud from a volcano that had erupted in the Aleutian Islands only a few days before. The ash, it turned out, had fertilized the ocean with thousands of tons of iron, on which the plankton gorged. [ScienceNOW]

Has climate skeptics’ favorite Danish statistician, Bjørn Lomborg, changed his stance? In the forthcoming book edited by Lomborg, Smart Solutions to Climate Change, he calls climate change one of the world’s “chief concerns” and suggests investing $100 billion annually on climate change solutions.

The suggestion certainly comes as a surprise. In his previous books, like The Skeptical Environmentalistand Cool It, Lomborgargues that anthropogenic climate change is real but that it isn’t a “catastrophe”–that the associated “hysteria” was causing us to spend money trying to curb the globe’s warming where it would have been better spent, say, feeding the hungry or curing HIV.

Understandably, that stance has made his work appealing to climate skeptics who don’t want to spend money on curbing emissions–and unpopular among those who see Lomborg as a distraction who misrepresents the science and confuses the issue. In his new book, the statistician apparently reorders his priorities, now arguing that climate change solutions should get more cash.

What’s not a surprise: opinions vary as to the merits of this new book and as to whether it’s a shift, a drastic shift, not a shift, or a publicity stunt. Here, we share some.

You could plant huge new forests where none have been before. You could blast particles into the sky to block the sun’s radiation. You could put mirrors in space. These planetary hacks could slow global warming, but one thing that none of them could do, most likely, is to stop the rising sea levels that a warming planet will bring.

That’s the contention of John Moore, lead author of a study out in the Proceedings of the National Academy of Sciences. Moore’s team examined five different means that scientists have proposed to hack the planet and save ourselves from anthropogenic global warming. The geoengineering schemes—forestation, atmospheric aerosols, space mirrors, biochar, and the use of biofuels plus carbon sequestration—are focused either on reducing the amount of energy the Earth absorbs or pulling carbon out of the atmosphere. So Moore wanted to see what they could do about a side effect of the extra heat: melting ice raising the global average sea level.

Schemes to hack the planet and save us from global warming have two layers of obstacles to overcome. First, is it technologically and physically possible to do what’s proposed? And then there’s the second: Is it politically possible to tinker with the planet?

Those who would argue “absolutely not” to the latter got a boost by a new study out in Nature Geoscience. Katharine Ricke and her team modeled the effects of one of the most popular geoengineering plans: seeding the atmosphere with aerosols to reflect away some of the sun’s rays, mimicking the way a massive volcanic eruption can cool the Earth. Ricke found that the effects on rainfall and temperature could vary wildly by region—and that what’s best for one country could spell disaster for another.

For example, Ricke says, her study found that levels of sulphate that kept China closest to its baseline climate were so high that they made India cold and wet. Those that were best for India caused China to overheat. She notes, however, that both countries fared better either way than under a no-geoengineering policy [Nature].

Bill Gates is getting serious about geoengineering. Back in January, after the failure of governments at the Copenhagen Climate Change summit to do anything serious, the billionaire former head of Microsoft announced he’s give nearly $5 million of his fortune to fund research into geoengineering projects. Recently he announced his first concrete foray into the field: giving $300,000 to project that would spray seawater into the sky, seeding clouds that would hopefully block some of the sun’s UV rays.

The machines, developed by a San Francisco-based research group called Silver Lining, turn seawater into tiny particles that can be shot up over 3,000 feet in the air. The particles increase the density of clouds by increasing the amount of nuclei contained within. Silver Lining’s floating machines can suck up ten tons of water per second. If all goes well, Silver Lining plans to test the process with 10 ships spread throughout 3800 square miles of ocean [Inhabitat].

Most of the major geoengineering ideas that have been proposed—launching a reflective shield into space, artificial trees to pull carbon dioxide out of the air—are extremely expensive and difficult.

However, a study last year calculated that a fleet of 1,900 ships costing £5 billion (about $7.5 billion) could arrest the rise in temperature by criss-crossing the oceans and spraying seawater from tall funnels to whiten clouds and increase their reflectivity [The Times].

As heated global warming debates continue, scientists are also investigating ways to get our planet to cool off if the politicians can’t figure out how to reduce greenhouse gas emissions. The latest geoengineering scheme involves turning the world’s oceans into a giant bubble bath, with hundreds of millions of tiny bubbles pumped into the seas. This would increase the water’s reflectivity and bring down ocean temperatures, according to Harvard University physicist Russell Seitz. As the creative physicist said to the assembled crowd at an international meeting on geoengineering research: “Since water covers most of the earth, don’t dim the sun…. Brighten the water.”

Seitz explained that micro-bubbles already occur naturally, with bubbles under the ocean’s surface reflecting sunlight back into space and mildly brightening the planet. What Seitz imagines doing now is artificially pumping many more bubbles into the sea. These additional micro-bubbles would each be one five-hundredth of a millimeter and would essentially serve as “mirrors made of air.” The scientists say they could be created off boats by using devices that mix water supercharged with compressed air into swirling jets of water. “I’m emulating a natural ocean phenomenon and amplifying it just by changing the physics—the ingredients remain the same” [ScienceNOW], Seitz said.

Of all the planet hacking possibilities floated as last-minute ways to stave off a climate catastrophe (building a solar shade for the Earth, injecting the atmosphere with sunlight-reflecting aerosols, etc.), iron seeding seems one of the more practical and feasible ideas. The scheme calls for the fertilization of patches of ocean with iron to spur blooms of plankton, which eventually die, sink, and sequester carbon at the seafloor.

However, worries over the consequences of tinkering with the ocean ecosystem have held up plans to attempt this. And now, in a study in the Proceedings of the National Academy of Sciences, researchers claim that such a plan could risk putting a neurotoxin into the food chain.

Iron seeders have targeted the large swaths of ocean surface with high levels of nitrate and low chlorophyll, where an injection of iron could potentially turn a dearth of plankton into a bloom. But too many phytoplankton can be a bad thing, especially when it comes to members of the genus Pseudonitzschia. This alga produces domoic acid, which it spews into the surrounding seawater to help it ingest iron [ScienceNOW]. Sea lions off California have gotten sick from the toxin. In Canada, three people died in the 1980s from eating shellfish that themselves had eaten Pseudonitzschia.